This is what I've learned this past year in my quest to keep my head hair free and irritation free.

Use slow, even strokes; never rush. Shaving with the grain prevents irritation and tends to produce the closest shave, but if your skin is sensitive, shave against the grain. If you have curly hair, like myself, be sure to shave extra carefully, as you may be more prone to irritation. Keep a mirror close by at all times to keep track of your progress. To minimize irritation and prevent nicks and cuts, pass over each area of your scalp only once.

Treat your scalp after the shave. Wash your head with soap and water and towel off again. If your scalp feels itchy or irritated, use a good aftershave lotion or skin lotion to soothe your skin and help it heal. Opt for aftershave products or skin lotions that contain aloe vera or vitamin E. Avoid aftershaves that contain alcohol. Alcohol dries out the skin, something you don’t want to happen after shaving off all your hair.

Don't forget to protect your scalp. I learned the hard way, so keep scalp clean, moist, and covered in extreme weather. And don't forget to apply sunscreen every time you leave the house, even in the winter.

This thread is a must for the novice. I've recently talked a few of my colleagues at work to give headshaving a go. Two of them did major damage to their scalp. Why? Cause they didn't proceed with caution and go slow and steady. They went over their heads with the razor several times against the grain.